Siheyuan (traditional courtyard house): Starting with the Korean War, returning home to take charge

The sea breeze, carrying a salty, fishy smell, whipped He Yuzhu's collar up. He stood at the entrance of the Shanghai Fusion Experimental Base, looking up at the gray-white building. The lightning rod's tip pierced the gloomy sky like a needle stuck in cotton. Chief Engineer Qian emerged from the building, his steps slower than usual. He walked up to He Yuzhu, opened his mouth, but didn't utter a sound, stepping aside to let him pass.

"Everything is ready, Director He."

He Yuzhu followed him inside. The fluorescent lights in the corridor hummed, casting a white glow on the tokamak cross-section diagram on the wall. Reaching the control room door, the moment the iron door opened, a blast of cold air mixed with the smell of electronic components rushed out. Inside sat a dozen or so people, silent. Chief Engineer Sun sat at the control panel, his right hand resting on the start button, not pressing it, his fingers trembling slightly. Chief Engineer Li stood behind him, his notebook clenched so tightly the edges were curled, his knuckles white. Several young technicians in the back row stared at the screens, some clenching their fists, others biting their lips.

He Yuzhu walked to the control panel and glanced at the screens. Temperature, pressure, magnetic field, neutron flux—all were at their standby values, as stable as straight lines. He looked at Chief Engineer Qian.

"Have all the roof tiles been replaced?"

Chief Engineer Qian nodded, his voice dry. "Twelve thousand pieces, ceramic-based composite material, all passed inspection. Hot isostatic pressing welding, no loosening." He paused, his Adam's apple bobbing slightly. "The welding parameters were five percent higher than the design values, so it should be even stronger."

He Yuzhu didn't reply. He turned to Chief Engineer Sun.

"Let's begin."

Chief Engineer Qian walked to the control panel and pressed the intercom button. His voice, slightly hoarse, came through the loudspeaker: "Attention all positions, countdown begins. Ten, nine, eight..."

He Yuzhu stood at the back of the crowd. He saw Chief Engineer Sun's right index finger hovering above the button, not falling. He saw Chief Engineer Li clenching his notebook so tightly that the edges of the papers rustled. He saw a young technician in the back row take off his glasses, wipe them with the corner of his shirt, and then put them back on.

"...Three, two, one. Ignition."

Chief Engineer Sun pressed the button. The lights in the control room dimmed briefly, then returned to normal. The data on the screen began to fluctuate. The temperature soared from zero, ten million, twenty million, fifty million—when the pointer jumped over one hundred million, He Yuzhu heard someone gasp. The pressure followed suit, one atmosphere, ten, fifty, one hundred. The magnetic field strength jumped like a heartbeat, and the neutron flux curve bounced straight up from zero, almost vertically.

No one spoke in the control room. Everyone stared at the neutron flux curve.

It skipped the design value of 1.0 and kept climbing. 1.2, 1.5, 2.0. When it stabilized at 2.1, He Yuzhu saw Chief Engineer Sun's shoulders slump down a bit, as if he had finally put down a heavy load he had been carrying for a long time.

"What about the Q value?" He Yuzhu asked.

Chief Engineer Qian lowered his head and flipped through the notebook, his hands trembling. He turned two pages but couldn't find the right one. Chief Engineer Li handed him the notebook from the side, pointing to a line. Chief Engineer Qian glanced at it, his throat tightening.

"5.2".

There was a two-second silence in the control room. Then someone stood up, pushed their chair back with a creak. Someone slammed a notebook on the table. Someone shouted, but it was unclear what they said. Chief Engineer Li threw the notebook into the air; the pages scattered and floated down, landing on his head and shoulders. He didn't flinch, just stood there grinning. Chief Engineer Sun sat at the control panel, his right hand still on the button, his mouth agape.

He Yuzhu didn't move. He stared at the temperature, pressure, and neutron flux on the screen. They had stabilized, like a few straight lines.

"How long did you run?"

Chief Engineer Qian glanced at the timer. "Three hundred seconds. The design target has been reached."

He Yuzhu turned around. "Keep running."

Chief Engineer Sun paused, removed his hand from the button, then put it back. "Dean, the design time is only three hundred seconds..."

"Run until something goes wrong. If we stop now, we don't know where the limit is."

Chief Engineer Qian opened his mouth, as if to say something, but didn't. He glanced at He Yuzhu, swallowed his words, and turned back to stare at the screen.

Four hundred seconds. Five hundred seconds. Six hundred seconds. The neutron flux began to fluctuate, jumping up and down by three percent. He Yuzhu stared at the curve, saying nothing. Seven hundred seconds, the fluctuations intensified, jumping to five percent. Eight hundred seconds, the temperature dropped by two million degrees.

"Stop," He Yuzhu said.

Chief Engineer Sun pressed the stop button. The numbers on the screen dropped, and the temperature, pressure, and neutron flux slowly decreased. The cheers in the control room had long since stopped; some people went to get water, some leaned back in their chairs and closed their eyes, and some squatted on the floor picking up scattered pieces of paper.

He Yuzhu walked out of the control room and leaned against the corridor wall. He lit a cigarette, but didn't smoke it; he held it between his fingers, watching the butt burn. Chief Engineer Qian followed him out and stood beside him, saying nothing.

"Let's go in and take a look." He Yuzhu stubbed out his cigarette.

They donned protective suits and entered the tokamak hall. The reactor was still dissipating heat, and the air was thick with the pungent smell of ozone. A technician inserted an endoscope into the vacuum chamber, and the surface of the first wall appeared on the screen. He Yuzhu leaned closer to examine it. The tiles were smooth, black, and without any cracks.

"Next piece."

The technician moved the endoscope. One, two, ten, fifty, one hundred. When it reached the three hundredth tile, a thin line appeared on the screen. Very short, like a hair, clinging to the edge of the tile.

"Stop." He Yuzhu pointed to the pattern. "Zoom in."

The technician zoomed in on the image. The crack edges were smooth, without branches, like a knife cut. Chief Engineer Qian leaned closer, staring at the screen, his Adam's apple bobbing again.

"Continue the investigation." He Yuzhu straightened up.

The technician examined each tile one by one. He Yuzhu stood beside him, not leaving. Time passed slowly as the endoscope moved within the vacuum chamber, the tiles flashing across the screen. After examining the last twelve thousand tiles, the technician looked up, his voice strained.

"Forty-seven pieces have cracks. They are all on the edge, and the length is less than one millimeter."

Chief Engineer Qian opened his notebook and traced lines on the paper with his finger. "The design specifications allow for two percent, this is less than 0.5%. It's usable."

He Yuzhu didn't speak. He walked to the observation window and looked at the wall inside covered with tiles. Each tile represented a car, forty-seven tiles, forty-seven cars. Chief Engineer Qian stood behind him, waiting.

"It can be used. But it needs to be replaced. Check it regularly, and replace it as soon as you find a crack. Don't wait until something goes wrong before replacing it."

Chief Engineer Qian nodded. "Okay. I'll arrange for spare parts; we'll replace them as we use them."

He Yuzhu took off his protective suit and walked out of the hall. The sea breeze hit him, dispersing the ozone smell. He walked to the beach, lit a cigarette, and smoked it this time. The smoke was scattered by the wind and quickly disappeared. Yang Xiaobing walked up from behind, stood next to him, and handed him a telegram.

"Commander, we've received news from Brazil."

He Yuzhu took the telegram. Pu Zheng was departing for Brasilia to meet with American representatives to discuss creating greater unrest in China. He folded the telegram and put it in his pocket.

"When did this happen?"

"Three days ago, the overseas Chinese saw him board the plane."

He Yuzhu stubbed out his cigarette and threw it into the sea. He looked at the gray sea in the distance, where fishing boats bobbed up and down in the waves.

"He moved."

Yang Xiaobing didn't speak. The sea breeze blew into the space between them, flipping up his collar.