By Bobbie Ann Mason

Random House. 266 pp. $24.95

In An Atomic Romance, her first novel in over a decade, Bobbie Ann Mason once again casts her level gaze across the western Kentucky landscape. This time the award-winning author squints beyond bargain outlets and finds an incendiary subject rooted among the Wal-Mart superstores: a uranium-enrichment plant.

Reed Futrell is a macho, easygoing maintenance engineer at the plant, where highly toxic leaks of beryllium have been reported on the national news. Reed, who loves escaping on his motorcycle, has been exposed plenty of times. Despite the fact that his father died at the same plant years earlier, he remains casual: "If I've got it, I've got it."

His new girlfriend, Julia, a biologist, wants him to get his blood tested, but he jokes that she'll have to draw the blood. " 'Won't you stick me, honey?' he said, running his hand down her back."

Reed's likable, feisty mother, meanwhile, has suffered a major stroke after several mini-strokes; her fight to regain independence gives this novel its beating heart.

The plant has been a steady provider of jobs, so the townsfolk try their damnedest to ignore the deformed frogs in their ponds and the "eerie blue flames" that erupt during rainfall, "licking the metal junk" of contaminated scrap heaps.

Mason clearly bases this plant on the Paducah Gaseous Diffusion Plant, about which she wrote an essay for the New Yorker in 2000. A former journalist, she effectively details Reed's job of repairing equipment in the Cascade, a 600-mile complex of pipes that makes up the uranium enrichment system. "Powerful electric motors sent the [uranium hexafluoride] gas spinning and shooting through hundreds of axial-flow compressors and into converters, where barriers with tiny holes filtered out the heavier isotopes. . . . This was the system, his friend and his enemy."

But despite these details, the novel is rather thinly plotted and populated. Its success rests on the shoulders of the protagonist, Reed, who is often alone. The chapters are carried along by brisk exposition that reads well, albeit schematically: A character's longings arise because of what we're told rather than what we witness. We're given a flashback snippet of Reed's and Julia's first meeting and their witty repartee about Stephen Hawking and string theory, and then we have to take it on the author's word that they are a rousing, perfect match, physically and intellectually. The one area where emotions are authentically demonstrated without mediation lies in the interaction between Reed and his mother, whom he not only loves but delights in.

Mason is a good-natured observer whose narratives are braided with the quotidian routine of consumer culture. Her distinct style, sometimes unfairly tagged Kmart fiction or Hick Lit, greatly influenced short-story writing in the '80s. Eager, overly ironic imitators misread Mason's eagle eye, however, mistaking her type of detail as a minimalist code for condescension. While a typical Mason character might relax in a Barcalounger, for example, in Mason's hands this would never mark a way to pass judgment on a character's social class or aspirations.

But just as Mason transcends stereotypes, she pays a price for her fair-mindedness: By being nonjudgmental she runs the risk of skating on the surface. Her characters tend to fret about TV shows, they muse about big jugs of hair-care products, and they fancy themselves in music videos. Such pop-culture totems stand, not always successfully, as proxies for more complicated emotions.

In this novel, the characters are captivated by quantum mechanics and the awesome dark power of plutonium, but their fascination is turned on and off like Reed's screen saver of photographs from the Hubble telescope. Indeed, these descriptions of distant galaxies and nebulae are so spotlighted that Mason telegraphs the fact that she will be relying on this metaphor more than once.

As the novel closes, the characters are faced with a new development that requires a major life decision. But the full gravity of this is barely skimmed in a conversation that concludes the book. What insights Mason has into characters facing mid-life will have to wait until next time. Both Reed and Julia are in their mid-forties, with grown children, but Mason handles them the way much younger, emerging authors build their characters: as free agents accruing experiences rather than as older adults working out the tangled consequences of those experiences.

This is a disappointment, especially since she has always been so good at portraying elderly characters handling whatever old age dishes out. Reed's mother is reminiscent of Lila in Mason's third book of fiction, Spence + Lila. The aging Lila, stuck in the hospital for most of the narrative, has no motorcycle to hop on, and we're glad she doesn't. Her experiences can't steal past her like road signs but are collected one on top of the other. In the final scene, Lila longingly plunges her hands into the soil of her garden: These nourishing deep layers form Bobbie Ann Mason's native turf and shouldn't be kept hidden from view. *

Nancy Zafris is the fiction editor of the Kenyon Review; her latest novel is "Lucky Strike."